The present invention relates to a method for bidirectional data transmission of a data set between a data transmission device and a data reception device via at least one packet-oriented network device.
Although applicable to arbitrary telecommunications devices, the present invention and the problems fundamental to it will be described here with reference to a radio connection in mobile radio networks.
Fundamentally, there are two different types of data transmission. One is connection-switched or -oriented transmission, and the other is packet-switched or -oriented data transmission.
In connection-oriented data transmission, a permanent connection exists between the data transmission device, in particular a modem or a mobile phone, and the data reception device, and the data transfer takes place via this permanent connection. This connection is made at the beginning, for instance via a mobile radio network, and is terminated again after the data transmission has been accomplished.
In packet-oriented data transmission, the data transmission device and the data reception device are not connected directly to one another via merely a connection but rather via at least one network, which is used by a plurality of data transmission devices and data reception devices. The data to be exchanged are combined into packets for a data transmission and directed via appended address information from the data transmission device to the data reception device. Data packets from different data transmission devices and data reception devices can thus be transmitted via an identical transmission medium. Only so-called logical connections exist in this case.
The advantage of the aforementioned connection-oriented data transmission is that a guaranteed data transmission capacity is available to a corresponding user or device at any time.
The advantages of the packet-oriented data transmission, also mentioned above, are improved data transmission efficiency between the amount of data and the data transmission capacity; that is, if the data transmission capacity is not exhausted by one logical connection, then the remaining capacity can be used by other logical connections as well.
Thus voice transmission services are typically made available virtually exclusively with the aid of connection-oriented data transmission, while services in the field of information technology, such as computer linking or internet access, utilize packet-oriented data transmission.
The networks known as the Public Switched Telephone Network (PSTN), the Integrated Services Digital Network (ISDN) and the Global System for Mobile Communication (GSM) offer connection-oriented services, for instance for voice transmission, fax transmission, and so forth.
Conversely, a local area network (LAN) and wide area network (WAN) offer packet-oriented services. These include the network known as General Packet Radio Service (GPRS) as a supplement to the Global System for Mobile Communication (GSM); the GPRS makes packet-oriented services possible from the service provider, for instance from the internet, to a mobile terminal by way of the network operator and a radio connection, for instance.
The problems fundamental to the present invention are above all in creating a possibility for direct use of packet-oriented networks by the user even if one part is switched in connection-oriented fashion.
At present, the following initial attempt exists in the prior art for solving this problem.
Via connection-oriented services, typically various selection choices are available, such as a modem connection via the PSTN, which offers access to the internet, for instance via a personal computer or laptop, via an internet service provider (ISP), for instance. For the personal computer or laptop, in comparison to direct packet-oriented network connection, there is no difference, since the data transmission packets can be transmitted “encapsulated”, that is packed by means of a data protocol, via the connection-oriented network. Known protocols for this “encapsulation” of the data transmission packets are for instance the point- to- point protocol (PPP) or serial line internet protocol (SLIP). These protocols are allocated by the user to the data packets to be transmitted and are taken from a selection node, for instance at the internet service provider.
In the above attempt, the fact that the network operators that offer both packet-oriented and connection-oriented services must make both nonuniform addressing mechanisms and inefficient data transmission available, since they must transmit packet data in connection-oriented fashion, for instance to the internet service provider (ISP), even though packet-oriented switching may under some circumstances be present, has proved disadvantageous.